Howard Richmond, my search results read, started out in show business as a press agent. From there, he branched out into music publishing.

In my ignorance I must confess that I don't know who Harold Leventhal is/was, it is safe to presume that these are two different individuals. Both had long associations with the Weavers.

I apologize for my error, by the way: when MGM-Lion expressed his frustration about identifying "Joel Newman," the song under discussion was "Kisses Sweeter Than Wine," not "Wimoweh" which is covered on a different Mudcat forum thread.